This is not an error while trying to load a JSON library, but rather a Python syntax error caused by differences between Python 2 and Python 3 that happens to occur on a raise
line. See the two lines that follow the raise
line:
raise ImportError, "Can't load a json library"
^
SyntaxError: invalid syntax
Tweepy only supports Python 2:
Note only Python 2.6 and 2.7 are supported at the moment. The Python 3 family is not yet supported.
If you intend to work with Twitter using Python 3, I invite you to review this list of libraries from the Twitter developer site. In general, most libraries that support Python 3 will advertise that fact.